B4 Flashcards
What is photosynthesis?
An endothermic reaction in which energy is transferred from the environment to the chloroplast by light
What is the equation for photosynthesis?
Carbon dioxide+ water—> glucose +oxygen
What is the symbol equation for photosynthesis?
6CO2 + 6H2O —> C6H12O6 +6O2
What are the five ways that plant uses glucose?
Respiration
cellulose
amino acids
stored as oils or fats
stored as starch
What are the four limited factors of the rate of photosynthesis?
Temperature
light intensity
concentration of carbon dioxide
Amount of chlorophyll
How does temperature affect the rate of photosynthesis?
Increasing the temperature increases the rate of photosynthesis as the kinetic energy of particles is increase. The rate decreases past a certain temperature as enzymes become denatured.
How does light intensity affect the rate of photosynthesis?
Increase the light intensity increases the rate of photosynthesis until another factor becomes limiting
How does carbon dioxide concentration affect the rate of photosynthesis?
Increase in the carbon dioxide concentration increases the rate of photosynthesis until another factor becomes limiting as carbon dioxide is required to make glucose
How does the amount of chlorophyll affects the rate of photosynthesis?
Decreasing the amount of chlorophyll decreases the rate of photosynthesis as chlorophyll is required to absorb light energy
What is a limiting factor?
An environmental factor which can restrict the rate of photosynthesis
How can you show that a plant gives off oxygen during photosynthesis?
Use a water plant collect gas bubbles produced during photosynthesis. This gas will relight with a glowing splint as it contains oxygen.
How can you calculate the rate for photosynthesis by measuring oxygen produced?
Set up pond weed in a sealed tube of water attached to a capillary tube and a gas syringe Oxygen gas produce causes the bubbles in the capillary tube to move the distance moved by the bubble is used to calculate the volume of oxygen produced.
How can farmers increase their profit rates by knowing the limiting factors of photosynthesis?
They can control the temperature, light intensity and carbon dioxide concentration to achieve the fastest possible rate of photosynthesis leading into a great yield E.g. greenhouses
What is aerobic respiration?
Exothermic reaction in which glucose reacts with oxygen to release energy which can be used by cells
What is the equation for aerobic respiration?
Glucose+oxygen—> carbon dioxide+ water (+energy)
Where does aerobic respiration take place?
In the mitochondria
Why do organisms require the energy released by respiration?
Synthesis of large molecules (chemical reactions)
Muscle contraction
Maintenance of body temperature
Active transport
Movement
What is anaerobic respiration?
An exothermic reaction in which glucose is broken down to release energy in the absence of oxygen
What is the equation for anaerobic respiration?
Glucose—> lactic acid (+energy)
Why is anaerobic respiration less efficient than aerobic respiration?
Glucose cannot be completely broken down so less energy is transferred
Why can anaerobic respiration lead to muscles feeling fatigue?
Lactic acid builds up in muscles preventing efficient contraction
What is an oxygen debt?
The amount of oxygen needed to convert lactic acid back into glucose after anaerobic respiration
What is fermentation?
A type of anaerobic respiration that occurs in plant and yeast cells
What is the equation for fermentation?
Glucose—>ethanol + carbon dioxide
What is fermentation used for?
used in the production of bread and alcoholic drinks
what are the three things that increase during exercise?
Heart rate, breathing rate and breath volume
Why does the heart rate, breathing rate and breath volume increase during exercise?
To supply the muscles with more oxygenated blood
What occurs if there is insufficient oxygen?
Anaerobic respiration takes place in the muscles
What happens to the lactic acid that is produced by anaerobic respiration in the muscle?
Blood flowing through the muscles transports the lactic acid to the liver where it is converted back into glucose
How do muscles store glucose?
As glycogen
What is a metabolism?
The sum of all the reactions that take place in a cell or an organism
How do cells use energy transferred by respiration?
To continuously carry out enzyme controlled processes which lead to the synthesis of new molecules
What reactions does metabolism include?
Conversion of glucose to starch glycogen and cellulose
The conversion of glycerol and fatty acids into lipids
The use of glucose and natural ions to form amino acids
Photosynthesis
Respiration
Breakdown of access proteins to form urea
when is light a limiting factor?
during the night
when is temperature a limiting factor?
during the winter
how do farmers control temperature using greenhouses?
use a heater in the winter and use a ventilator and shade during the summer
how do farmers control light intensity using greenhouses?
by using an artificial light after the sun goes down
how do farmers control carbon dioxide concentration using greenhouses?
using a paraffin heater to heat up the greenhouse and as it burns it makes carbon dioxide
why is the greenhouse being enclosed a positive thing?
they keep the plants free from pests and diseases, farmers are also able to add fertilisers to the soil so the plants have all minerals needed for growth
